Electric circuit for motor vehicles



March 27, 1945. R. LlNDER 2,372,438

ELECTRIC CIRCUIT FOR MOTOR VEHICLES Filed April 4, 1940 ,lz ven Z01 RUDOLF A /NDER v4 i iorney Patented Mar. 27, 1945 ELECTRIC CIRCUIT FOR MOTOR VEHICLES Rudolf Linder, Stuttgart-Degerloch, Germany;

vested in the Application 1 Claim.

tween zero and parking light, bright light, dim

light etc.

It is an important object of the present invention to provide means, in a plant of the type referred to, by which the voltage available at the terminals of the head lights can constant under any conditions, independently from the charging conditions of the battery and the distance from the light switch to the head lights.

With this and further objects in view, as may become apparent from the within disclosures. the invention consists not only in the structures herein pointed out and illustrated by the drawing. but includes further structures coming within the scope of what hereinafter may be claimed.

The character of the invention, however, may be best understood by reference to one of its practical forms, as illustrated in the accompanying circuit diagram.

The invention, in a broad aspect, contemplates,

in combination, the provision of means for ad- 1 justing the voltage regulator for the electric gerierator, by means of said light light switch, to produce a lower voltage in the night position of the light switch than in the day position thereof, and the provision of an electromagnetic switch or circuit breaker under control of the light switch, to permit the current to flow from the generator directly, through said electromagnetic switch, to the head lights, without taking the detour through the light switch on the switch board of the driver. In this manner, it is possible to supply to the head lights a substantially conbe maintained be operated from the stant voltage which practically is not influenced by the charging conditions of the battery. with a minimum voltage drop.

Referring now to the drawing in greater detail. it will be noted that the plant comprises a light dynamo I including a field coil 2 and, in series therewith, a resistance 3 that can be short-circuited by an electromagnetic voltage regulator 4 which in turn includes a normal voltage coil 5, an

additional voltage coil 6 having a magnetising effect assisting that of coil 5. an armature 1 and two regulator contacts 8, 8. interpolated be- Alien Property Custodian April 4, 1940, Serial No. 327,777 Germany April 21, 1939 tween the light dynamo l and a battery in is an electromagnnetic charging switch 9.

Provided on the front side of the motor vehicle are a pair of bright head lights H, H for road illumination in the open country and a pair of dimmed or city head lights l2, l2. Advantageously, two-filament dimming lamps of the type known, for example, under the trade name of Bilux lamps are used for this purpose, one bulb of this type being installed in each main head lamp. For the sake of clarity the additional sources of light usually present on a motor vehicle, such as, parking light, tail light, additional search light, etc., have been omitted.

The circuit is controlled by an electromagnetic switch 13 comprising two voltage coils l4 and i5 magnetising their core in the same sense, as well as an armature l6 whose contact 11 cooperates with a contact 19 on a contact spring 18. Moreover, a double contact 20 on the spring 18 cooperates with two stationary contacts 2 l 22.

Mounted in the reach of the driver, for example, on the switch board, is a light switch 23 including a contact cylinder 24 provided for four switch positions, viz-0, I, II and III which are 0 all off, I driving in daylight, II Parking by night" and III driving by night. The contact cylinder 24 has a plurality of contact segments mounted on its circumference and partly covered with insulating material, as shown, for cooperation with stationary contacts 25 and 26. The contacts provided on the light switch for other purposes besides the head light switching are not shown in the drawing. A dimming switch 21 to driver and including a contact 28 serves for switching over from bright to dim light and vice versa. The open position as shown is for bright light and dimming is effected by closing the contact 28.

In the position as shown in the drawing, the light switch 23 is set for day-time driving. In this case, the contact 26 engages an insulating segment, and the connection to the two coils l4 and I5 of switch I3 is cut on. As a result. the switch l3 takes up the position indicated in the drawing, interrupting supply to the head lamps il, l! and l2, l2 and interrupting the connection to the coil 6 of the voltage regulator I. In this condition. the regulator 4 is influenced merely by the coil 5 and, by periodically switchin on and off the resistance 3, regulates the volta e of the generator to a value of, say 7.5 v., thus ensuring full charging of a three-cell lead battery by day-time driving.

In the night-time driving position of the light switch 23, the two contacts 25 and 26 are interconnected by the conductive portions on the contact cylinder 24, thus closing the circuit of coil 15 of switch I 3. Supposing the dimming switch 21 is open, the coil I4 of switch [3 is switched oiT. The magnetic flux generated by the coil l causes attraction of the armature IE to such an extent that the contacts l1, l9, are closed, while the contacts 20, 2|, of the contact spring still remain closed. Consequently, the two head lamps H, H are connected to the battery I 0, or, with closed charging switch 9, to the generator I. At the same time, coil 6 of l9, IT, with the battery I0. Hence, the regulator 4 is now influenced by the two coils 5 and 6 and regulates the voltage of generator I to assume a lower value than with day-time driving, namely, the nominal tension of the of the generator to a voltage of 6.75 volts.

By opening the dimming switch 21 the head lamps may then be switched back to bright light.

It will thus be understood that the generator responding to their nominal voltage, independently from, the charging condition of the battery, so that variations in the light intensity of the lamps are prevented. Owing to the low voltage of the generator the charging current supplied cannot grow to excessive figures, a result, overloading of the generator is avoided in spite of the additional load produced by the head lamps.

Sufiicient charging of the battery is ensured by the fact that the generator is regulated to produce a considerably higher voltage at daytime driving.

It will be seen from the drawing that the electromagnetic switch I3 which is the light switch 23 permits a direct connection ply cable to be passed over the light switch 23. Hence, any voltage by the length of cable required for this connection, by the light switch, etc., is avoided.

The apparatus of the present invention has been described in detail with reference to specific embodiments. It is to be understood, however, that the invention is not limited by such than those speand illustrated in the draw- I claim:

In an electric lighting system incorporating a variable speed generator, 3, storage battery, an

voltage winding for modifying the regulation, two translating devices of difierent current capacity, circuit connections RUDOLF LINDER. 

